I have been repairing these F3 bodies for over 10 years now and have run into something I have never seen before and can't seem to repair. This post is only for the experienced ones with some working knowledge of the inards of this camera.
Upon initial inspection the camera would not fire with the top shutter button, but would with the mechanical release lever - not an unusual situation for these bodies. The advance arm will wind and cock the shutter, only to be released only by the mechanical lever. I pulled the bottom plate, along with the battery box to inspect the wiring, etc. Battery chamber was clean and all wires appeared to be intact. Upon insertion of two new batteries, the voltage measured on the flex circuit board where the two battery wires are soldered measured 3.15 volts. So the power supply seemed ok.
I then removed the top right plate to inspect the shutter release button, on/off switch, and even further down into the 2nd curtain release magnet, etc. Nothing appeared out of the ordinary. I cleaned everything, including the magnet contacts just to be sure. Reassembled and still the same problem.
I then attached an MD-4 with new batteries and it would not fire either. However, the mechanical release would still work. Now it gets weird. Every time I use the mechanical release mechanism, it fires the shutter exactly two times in succession (with the MD-4 on S mode). After doing this repeatedly for about 10 reps the MD-4 suddenly kicked in and started to fire the shutter. Both single and continuous modes worked. Then suddenly the shutter button on top of the camera began to work as well. I immediately removed the MD-4 and the shutter button continued to fire the shutter as it should, on all speeds. However, if I would set the camera down and let it rest say for 2 or 3 minutes, then attempt to use the shutter button again, it would not fire. It acted just like when I initially got it. I have repeated this chain of events and it always works the same. So clearly the magnetic shutter release is functioning.
I then removed the power transfer switch on the bottom of the camera. That is that thing under the black motor drive cap with all the pin contacts that switches the power from the internal batteries of the camera to the motor drive power supply. I have some new parts in store so I replaced the entire assembly. Still the same problem with sporadic functionality.
I then split open the camera and removed the front plate, exposing the entire insides of the camera. I checked all the mirror functions, shutter mechanism and even removed and cleaned the 1st curtain magnetic release. Everything seemed ok and all measured voltages are correct. I then re-assembled only to have the same problem persist. I also checked the FRE and it is good. At times everything works just fine, then when I let the camera sit for a few minutes and it all stops.
Anybody have any ideas, no matter how hair brained they are? Matt
Upon initial inspection the camera would not fire with the top shutter button, but would with the mechanical release lever - not an unusual situation for these bodies. The advance arm will wind and cock the shutter, only to be released only by the mechanical lever. I pulled the bottom plate, along with the battery box to inspect the wiring, etc. Battery chamber was clean and all wires appeared to be intact. Upon insertion of two new batteries, the voltage measured on the flex circuit board where the two battery wires are soldered measured 3.15 volts. So the power supply seemed ok.
I then removed the top right plate to inspect the shutter release button, on/off switch, and even further down into the 2nd curtain release magnet, etc. Nothing appeared out of the ordinary. I cleaned everything, including the magnet contacts just to be sure. Reassembled and still the same problem.
I then attached an MD-4 with new batteries and it would not fire either. However, the mechanical release would still work. Now it gets weird. Every time I use the mechanical release mechanism, it fires the shutter exactly two times in succession (with the MD-4 on S mode). After doing this repeatedly for about 10 reps the MD-4 suddenly kicked in and started to fire the shutter. Both single and continuous modes worked. Then suddenly the shutter button on top of the camera began to work as well. I immediately removed the MD-4 and the shutter button continued to fire the shutter as it should, on all speeds. However, if I would set the camera down and let it rest say for 2 or 3 minutes, then attempt to use the shutter button again, it would not fire. It acted just like when I initially got it. I have repeated this chain of events and it always works the same. So clearly the magnetic shutter release is functioning.
I then removed the power transfer switch on the bottom of the camera. That is that thing under the black motor drive cap with all the pin contacts that switches the power from the internal batteries of the camera to the motor drive power supply. I have some new parts in store so I replaced the entire assembly. Still the same problem with sporadic functionality.
I then split open the camera and removed the front plate, exposing the entire insides of the camera. I checked all the mirror functions, shutter mechanism and even removed and cleaned the 1st curtain magnetic release. Everything seemed ok and all measured voltages are correct. I then re-assembled only to have the same problem persist. I also checked the FRE and it is good. At times everything works just fine, then when I let the camera sit for a few minutes and it all stops.
Anybody have any ideas, no matter how hair brained they are? Matt
